Little Long Lake
Little Long Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 21 ft visibility. Maximum depth: 45 ft. Surface area: 322.24 acres.
- Clarity
- 21 ft
- Max depth
- 45 ft
- Area
- 322 acres
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 28
- Open water
- 215 days
Next lake in St. Louis County
Why Little Long Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Little Long Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Little Long Lake is a 322-acre lake in St. Louis County, Minnesota with a maximum depth of 45 feet. Overall water quality is declining over recent sampling years. The lake supports 11 documented fish species including black crappie, bluegill, and green sunfish. Public access is available with 2 public boat landings.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-11-05. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Little Long Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Crystal clear, you can see 21 ft down. Trophic State Index: 33.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 21 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 33 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Little Long Lake
Compare lakeside cabins, hotels, and vacation rentals near Little Long Lake in St. Louis County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 45 ft |
| Surface Area | 322 acres |
| Shoreline Length | 6.5 mi |
| Littoral Zone | 24% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Shagawa Lake (Northwest)Public
- Little Long LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Little Long Lake
DNR Fisheries Survey Summary
10 surveys on file from MN DNR Fisheries. Most recent: 2025-08-01 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| RBS | 102.98 | 0.03 lb |
| Bluegill | 46.78 | 0.1 lb |
| Smallmouth Bass | 17.15 | 0.96 lb |
| Tullibee (Cisco) | 10.16 | 1.42 lb |
| CNM | 9.93 | — |
| Walleye | 6.90 | 3.29 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
RBS
Bluegill
Smallmouth Bass
Tullibee (Cisco)
From the 2025-08-01 survey
Temperature and dissolved oxygen measurements were collected from the deepest basin in Little Long Lake on August 1st, 2025. This was done to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Little Long Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Little LongFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Little Long (1892)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — Little LongFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Little LongPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.354 m/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (22 observations).
Estimated open water season: 215 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2006-04-16 (2006) | 2022-05-13 (2022) |
| Ice-In | 2014-11-19 (2014) | 2022-12-06 (2022) |
Most recent ice-out: 2023-05-09
EPA Impairment Status
Little Long Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN69-0066-00 · Official waterbody report
Graded lakes near Little Long Lake
Little Long Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in St. Louis County
Frequently asked questions about Little Long Lake
What is the water quality grade for Little Long Lake?
- Little Long Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 21 ft visibility. Maximum depth: 45 ft. Surface area: 322.24 acres.
Is Little Long Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Little Long Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Little Long Lake?
- Little Long Lake has a maximum depth of 45 feet. The lake covers 322.24 acres.
What fish are in Little Long Lake?
- Fish species found in Little Long Lake include black crappie, bluegill, green sunfish, largemouth bass, northern pike, rainbow smelt, rock bass, smallmouth bass, walleye, white sucker, yellow perch. Little Long Lake is located in St. Louis County, Minnesota.
When does Little Long Lake thaw?
- Little Long Lake typically has ice-out around Apr 28. Ice typically forms around Nov 29. The open water season is approximately 215 days.
Are there boat ramps on Little Long Lake?
- Little Long Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Shagawa Lake (Northwest), Little Long Lake. Public access is listed as yes.
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Where this data comes from
44 measurements from 4 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA44 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (4)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate